Our long-term research program has had two intertwined general aims: (a) to learn what sorts of bacteria are phytopathogenic, including their relationships to other (nonphytopathogenic) bacteria; and (b) to learn the mechanismic bases for their pathogenicity. During this next Project Period (probably my last one!), we hope to distill from some four decades of prologue the answers to the "big" questions. Many detours have been necessary to reach this point. Numerous disciplines that by convention were outside the contemporary mainstreams of phytopathogenic bacteriology (or bacterial phytopathology) had to be mastered and applied to the program. These detours range from pigment chemistry to conjugational genetics, from enzymology to human pathobiology, from ecology to computer taxonomy, from bacteriophage to Bdellovibrio, from electron microscopy to metabolism. The specific aims during this (final) Project Period fall generally into the class of synthesis. Taking everything we have learned into account, we will try to provide the best specific summary statements that relate to the general aims.